Antibacterial and antifungal activity of pinosylvin, a constituent of pine

The antibacterial and antifungal activities of pinosylvin (3,5-dihydroxy-trans-stilbene), a constituent of pine, were studied and compared with those of resveratrol (3,5,4'-trihydroxy-trans-stilbene). Pinosylvin exhibited more potent growth inhibitory activity against Candida albicans and Saccharomyces cerevisiae.     

工厂化繁育香菇胶囊菌种专用培养基配方研究

在已筛选出的代料香菇胶囊菌种专用配方LSC1和LSC5基础上,设计了7种香菇胶囊菌种培养基配方,以L26为供试菌株,观察测试了菌丝生长速度、瘤状突起物形成时间与数量、菌种成型及在愈伤培养时的特征以及菌种持水性等特征指标,筛选出了适宜于工厂化繁育香菇胶囊菌种的专用培养基配方LSCG2T和LSCG3,并在胶囊菌种工厂化繁育生产线中进行了应用试验,取得了良好效果。试验结果表明,工厂化繁育胶囊菌种的配方中粗细木屑的比例应提高到5∶1,配方中应添加以提供微量元素和基质物理性能改良剂的辅料。     

在韩国片断化林区内道路对小型啮齿类种群的影响

The road effect on small rodent population is investigated at 8 fragmented forest areas in the Baekdudaegan moun-tain range, South Korea in September 2001, We especially focused on the distribution and body condition of small rodents near the roads, Korean field mouse (Apodemus peninsulae) seems to be more sensitive to the existence of a road than striped field mouse (Apodemus agradus), Korean field mouse prefers interior forest area to around road. Striped field mouse is a habitat generalist and has wide distributional range around road, but Korean field mouse is forest-inhabiting species and their distribu-tion is limited in forest area. These results suggest the effect of road is different on each small rodent species and their habitat preferences.     

Study on half-scale model test for light-frame shear wall

A half-scale model of a light-frame shear wall was developed to evaluate the racking performance of a fullscale shear wall (prototype). The effect of nail size on the performance of the shear wall was also investigated using models constructed with three types of nail. Materials for the model were determined through experimental methods, which included nail-head push-through, stud-to-sheathing nail connection, and static bending tests. Materials with which the model was made to be in similarity to the prototype were three-layer 4.8-mm plywood, 39.72-mm long nails, and 1 × 2 lumber cut from 2 × 4 studs. In accordance with ASTM E 72 and ASTM E 564, racking resistance tests were conducted on 20 shear walls. The results showed that the maximum load capacities of the prototype walls could be evaluated by the model without significantly different failure modes. Tests on the effect of nail size revealed that increasing the nail head diameter may improve the performance of shear walls.Parts of this paper were presented at the International Conference on Effective Utilization of Plantation Timber (ICEUPT'99), Chi-Tou, Taiwan, May 1999; and the World Conference on Timber Engineering (WCTE2000), Whistler, Canada, July–August 2000     

Growth and development of the arborescent cactus Stenocereus queretaroensis in a subtropical semiarid environment,including effects of gibberellic acid

In Stenocereus queretaroensis (Weber) Buxbaum, an arborescent cactus cultivated in Jalisco, Mexico, for its fruits but studied here in wild populations, stem extension occurred in the autumn at the beginning of the dry season, flowering and fruiting occurred in the spring at the end of the dry season, and new roots grew in the summer during the wet season. The asynchrony of vegetative and reproductive growth reduces competitive sink effects, which may be advantageous for wild populations growing in infertile rocky soils. Seasonal patterns of sugars in the roots and especially the stems of S. queretaroensis were closely related to the main phenological stages, becoming lower in concentration during periods of major stem extension. Cessation of stem extension occurred in 100-year-old plants for which injection of GA(3) reinitiated such growth. Isolated chlorenchyma cylinders had maximum extension in a bathing solution containing 0.1 &mgr;M gibberellic acid.     

浅议贵州森林旅游的深层次开发

在分析旅游文化与贵州森林旅游深层次开发相互关系的基础上，结合贵州森林旅游业发展的实际情况，阐述了贵州森林旅游深层次开发的必要性和可行性，提出贵州森林旅游深层次开发的设想和保障措施。     

The effects of poplar (P. trichocarpa × deltoides) on soil biological properties in a silvoarable system

A silvoarable experimental site in Buckinghamshire, England combined rows of poplar trees with an arable rotation. Soil properties were investigated using soil carbon and the bodysize of invertebrates. Four years after establishment, the soil within and 1 m from the tree rows has significantly higher soil organic matter and invertebrate populations. These effects do not extend far beyond the crown diameter.     

Prediction of bending properties for structural glulam using optimized distributions of knot characteristics and laminar MOE

This study established a prediction model for bending properties of glued-laminated timber (glulam) using optimized knot and modulus of elasticity (MOE) distributions of lumber laminate as the main input variables. For this purpose, knot and MOE data were investigated for all pieces of lumber that were prepared for glulam manufacturing, and statistical distributions of knot size, knot number in one lumber, and MOE of each laminate were optimized as distribution functions. These knot and MOE data were used as input variables in the prediction model for bending properties, and were also used in generating virtual glulam using the inverse transform method. Prediction of bending properties for glulam was carried out using the transformed section method, which is partially provided in ASTM D 3737 (Annex A4). Predicted values were compared with those from full-scale four-point bending tests for 60 six-layered glulams with 10 different laminar combinations. Finally, the allowable bending properties of glulam for each specific laminate combination were determined by calculating the fifth percentile of the modulus of rupture and the average modulus of elasticity from virtual test results of more than 1000 virtual glulams. From the results of this study, predicted bending properties for glulam and their distributions could be used for structural design in both allowable stress design and limit state design.